Mounting for electric bells and the like



Sept. 22, 1942. L. a. RICHMOND MOUNTING FOR ELECTRIC BELLS AND THE LIKE Filed Dec. 1, 1939 Patented Sept. 22, 1942 MOUNTING FOR ELECTRIC BELLS AND THE LIKE Louis E. Richmond, Shelby, Ohio, assignor to The Autocall Company, Shelby, Ohio, a corporation of Ohio Application December 1, 1939, Serial No. 307,040

3 Claims.

The present invention relates to an improved mounting for electric bells and the like, and has as its general object to provide a simple, in expensive and secure mounting for supporting an electric bell or similar unit on a side wall, ceiling or other supporting structure. In practically all large scale signal installations employing bells or other signal units for the purpose of fire protection signalling, supervisory control signalling, code calling, etc., the general practice is to enclose substantially all of the wiring of the system within conventional forms of conduit, using conventional-types of outlet boxes and other fixtures, substantially asin the case of electric power and light circuits. To facilitate the mounting of each electric bell in sucha system, and also to simplify the making of the electrical connections therewith, I preferably employ conventional outlet boxes-as the main supporting structures for the bells. To each outlet box I secure a special cover plate on which the bell unit has detachable mounting. cover plate and the bell unit are each provided with cooperating interlocking parts which'are movable into and out of interfitting engagement when the bell unit is givena predetermined motion relatively to the cover plate. In the preferred embodiment of the invention herein disclosed, this attaching or detaching motion is a rectilinear or straight line sliding motion of the bell unit substantially parallel to the front surface of the cover plate. In most instances the bell is installed in a vertical position on aside wall or other vertical surface, and in all such cases the bell unit is moved into interlocked engagement with the cover plate by'a sliding motion of the bell unit in a downward direction, so that it tends to remain in thisinterlocked posi-- tion under the action of gravity. Thus, there is no possibility of the bell unit becoming accidentally loosened from the cover plate by the vibration of the bell or by any other cause, but, instead, the bell unit can only be released by an upward sliding force exerted manually against the bell unit. The sliding type of interlock has the advantages of being positive in action, easy to engage and release, and inexpensive to construct.

As the bell unit completes its sliding motion into interlocked engagement With the cover plate, a pair of contacts carried by the bell unit move into engagement with a cooperating pair of contacts carried by the cover plate, thereby completing the circuit leading to the bell winding. The straight line sliding motion of the bell unit into its mounted position insures direct, positive The engagement of these cooperating contacts. Furthermore, the contacts are soconstructed and arranged that the engagement therebetween establishes a detent relation for holding the bell unit in its interlocked or socketed attachment to said cover plate.

Other objects, features and advantages of the invention will appear from the following detail description of one preferred embodiment thereof.

In theaccompanying drawing illustrating such embodiment:

Figure 1 is a front elevational View showing the bell unit mounted-on the cover plate of an outlet box;

Figure 2 is a side Viewof the same;

Figure 3 is an elevational view of the bell unit as viewed from the inner or reverse side thereof;

Figure 4 is a front elevational view'of the special mounting plate which is secured to the outlet box;

Figure 5 is a fragmentary perspective view showing the interlocking relation between the bell unit and the cover plate; and

Figure 6 is a fragmentary vertical sectional View on a larger scale showing the cooperativeengagement between the contacts carried by the bell unit and the contacts carried by the cover plate.

The bell unit is indicated in its entirety at III, the outlet box is designated I I, and the special cover plate for the outlet box is indicated at I2. The outlet box may be of any conventional form, either rectangular or round, and provided with the conventional knock-outs I4. Where the wiring conduit is concealed, the outlet box may be set into a recess in the wall, ceiling or other supporting surface I5; but where the wiring conduit is exposed the outlet box may, of course, be secured to the outer surface of said wall, ceiling, or the like. The-cover plate I2 is secured to the open front of the outlet box II by the screws I6 and IT. The screws thus pass either through the diagonally opposite holes indicated at l8, I8, or through the diagonally opposite holes indicated at I9l9', and thread into tapped holes 2| in lugs 22 which are bent inwardly from the side walls of the outlet box.

A large rectangular opening 24 is punched out of the lower central portion of the cover plate I2. Extending across the lower part of said opening is a contact supporting plate or bridge 25 composed of any suitable insulating material. This insulating support is fastened up against the-back or inner surface of the cover plate I2, being secured in place by the cap screws 25 which pass through the cover plate and through the insulating bridge and receive nuts on their inner ends. Rigidly mounted on the upper edge portion of said insulating support are the two stationary contacts 28, these being in the form of identical clips which are secured by rivets 29 or the like to the insulating support. The upper portions of these clips are bent rearwardly and then upwardly, as indicated at 28 in Figure 6, to form terminal extensions for receiving the terminal screws 3| by which the conductors 32 are connected with said contact clips. These terminal portions are inclined to tilt the screws 3| a sufficient amount to enable them to be rotated by a screw driver inserted from the front of the cover plate down through the opening 24. Bent obliquely outwardly from the lower portions of the contact clips 28 are the contact spurs or arms 28", the extremities of whichform the actual contacting surfaces adapted to be engaged by the movable contacts on the bell unit, which movable contacts will be later described.

The interlocking means carried by the cover plate l2 consists of a plurality of lugs 35 punched forwardly from the body of the plate. These lugs are shown arranged in two vertical rows of three each, the two lower pairs being preferably punched out of the side edges of the opening 24, although it will be understood that this arrangement is not essential. As best shown in Figure 5, the companion lugs in the two vertical rows extend forwardly and then laterally toward each other in the general configuration of hooks,'these successive pairs of hooks defining two vertically extending parallel guide-ways or socket-ways for receiving the coacting interlocking elements on the bell unit ID.

The bell unit Ill comprises the bell 38 which is detachably secured by a screw 39 to a box-like sheet metal housing 4|. This housing contains the coil 42 which is energized in the sounding of the bell, the housing 4| having its rear side open for mounting the coil therein, as shown in Figure 3. Extending through the coil is astationary tube 43, composed of brass or other nonmagnetic metal, and mounted for reciprocation within this tube is the magnetic core 44 which serves as the striker element for striking against the inner side of the bell. The lower end of the tube 43 is closed, while the upper end is left open for the reciprocation of the striking core outwardly into engagement with the bell. In the upright mounting of the bell, gravity serves to restore the striking core to its normal position in the lower portion of the tube, but for other positions of mounting of the bell, spring means may be disposed within the tube 43 or otherwise arranged to restore the striking core 44 to its normal position.

Viewing the bell unit from the side, as shown in Figure 2, it will be seen that the sheet metal housing 4| projects rearwardly beyond the rear edge of the bell 38, the rear edge of this housing carrying the movable contacts which coact with the stationary contacts 28, and also carrying the movable interlocking means which coacts with the stationary interlocking lugs 35. The lower wall of the sheet metal housing 4| has a downwardly extending flange 46 to which are secured the insulating strips 41 and 41. Fastened to these strips are the two contacts 48 which are adapted to move into and out of engagement with the contacts 28, these movable contacts having their upper ends 48' electrically connected with the terminals of the winding 42. As best shown in Figure 6, the lower extremities of said contacts 48 are formed with curved depressions or pockets 48" which are adapted to have resilient engagement with the diagonal spurs or arms 28" of the stationary contacts 28. When the movable contacts slide down along the stationary contacts to bring the depressed contact portions 48 into position overlying and engaging the diagonal contact portions 28", a resilient detent relation is established which yieldably or releasably holds the bell unit against accidental sliding motion in the reverse direction.

The interlocking means on bell unit In consistsof outwardly bent flanges 5| formed along the vertical side edges of the housing 4|. These flanges are adapted to have vertical sliding motion downwardly under the hook-shaped lugs 35, as shown in Figure 5, thereby establishing an interlocked or socketed relation between the bell unit and the mounting plate I2. The lower limit of the sliding motion of the flanges 5| under the lugs 35 is defined by the lower ends of said flanges striking the heads of the screws 2B26, the latter serving as limiting stops for the downward movement of said flanges 5|. In such final position of the bell unit, as determined by these limiting stops, the movable contact portions 48" have the aforementioned detent engagement with the stationary contact portions 28".

The provision of the extra holes at |9|9' in the mounting plate I2 is to enable the screws |6-|'| to be passed through these holes in the event that the outlet box H is installed in a position turned at a right angle to that shown, with the lugs 22 positioned under the holes |9-|9'. As an alternative embodiment of the invention, the plate |2 might be employed as an independent mounting element, separate from and not requiring the outlet box for its mount- 4(); ing on a wall or other supporting structure. Also, instead of a bell, the signal unit might be an electric chime, an electric buzzer, or other type of unit.

While I have illustrated and described what I regard to be the preferred embodiment of my invention, nevertheless it will be understood that such is merely exemplary and that numerous modifications and rearrangements may be made therein without departing from the essence of the invention.

I claim:

1. In a construction of the character described comprising, in combination, a mounting plate having means for attaching it to a wall or the like, said plate having a substantially rectangular opening therein, two rows of hook-shaped lugs punched forwardly from said'plate toform laterally spaced parallel' guideways extending upwardly of said plate along the side margins of said substantially rectangular opening, an insulating bridge extending across the lower portion of said opening, a pair of relatively stationary contacts mounted on said insulating bridge, an electrical unit adapted for readily removable mounting on said mounting plate and comprising electrically energized means, said electrical unit comprising a pair of substantially parallel flanges adapted for sliding engagement within the parallel guideways defined by said lugs, and a pair of movable contacts carried by said electrical unit and adapted to engage with said stationary contacts for completing electrical circuit connections with said electrically energized means.

comprising, in combination, a mounting plate having means for attaching it to a wall or the like, said plate having an opening therein, two rows of hook-shaped lugs punched forwardly from said plate to form laterally spaced parallel guideways extending upwardly of said plate adjacent the side margins of said opening, an insulating bridge extending across said opening, a pair of relatively stationary contacts mounted on said insulating bridge, said contacts having terminal screws which are accessible from the front side of said cover plate through said substantially rectangular opening in establishing electrical connection with conductors leading to said plate from the back side thereof, an electrical unit adapted for readily removable mounting on said mounting plate and comprising electrically energized means, said electrical unit comprising a pair of substantially parallel flanges adapted for sliding engagement within the parallel guideways defined by said lugs, and a pair of movable contacts carried by said electrical unit and adapted to engage with said stationary contacts for completing electrical circuit connections with said electrical energized means.

3. In a construction of the character described comprising, in combination, a mounting plate having means for attaching it to a wall or the like, said plate having a substantially rectangular opening therein, two rows of hook-shaped lugs punched forwardly from said plate to form laterally spaced parallel guideways extending upwardly of said plate along the side margins of said substantially rectangular opening, an insulating bridge extending across the lower portion of said opening, a pair of relatively stationary contacts mounted on said insulating bridge, said contacts having terminal screws which are accessible from the front side of said cover plate through said substantially rectangular opening in establishing electrical connection with conductors leading to said plate from the back side thereof, an electrical unit adapted for readily removable mounting on said mounting plate and comprising electrically energized means, said electrical unit comprising a pair of substantially parallel flanges adapted for sliding engagement within the parallel guideways defined by said lugs, and a pair of movable contacts carried by said electrical unit and adapted to engage with said stationary contacts for completing electrical circuit connections with said electrically energized means.

LOUIS E. RICHMOND. 

